Just as football legend's Junior Seau's death was officially ruled a suicide by investigators, a forensic pathologist who identified chronic brain damage as a factor in the deaths of some NFL players flew in to help with the autopsy.

The pathologist, Bennet Omalu, assisted in the autopsy conducted by the San Diego County medical examiner because of his experience with NFL players and brain injuries, well placed sources confirmed to ESPN late Thursday.

Omalu, the chief medical officer for San Joaquin County (Calif.), is credited with identifying Chronic Traumatic Encephalopathy (CTE), a neurological disorder stemming from repeated head trauma in several deceased NFL players.

CTE can lead to erratic behavior also associated with dementia and Alzheimer's disease.

It is expected to take 4-6 weeks to determine whether Seau suffered from CTE, and at this point, it is unclear who will make that diagnosis.

Seau's brain remains with the San Diego medical examiner and is not expected to be buried with Seau, according to the sources.

Another research group, the Sports Legacy Institute at Boston University, also seeks access to Seau's brain, Sports Illustrated reported Thursday.

SLI has received funding from the NFL. Chris Nowinski, a Harvard graduate and former professional wrestler who helped found the group, declined a request for an interview. Omalu and Bailes also declined comment.

Seau's family will allow researchers to study his brain for evidence of damage as the result of concussions, San Diego Chargers chaplain Shawn Mitchell said.

"The family was considering this almost from the beginning, but they didn't want to make any emotional decisions," Mitchell told The LA Times.

"And when they came to a joint decision that absolutely this was the best thing, it was a natural occurrence for the Seau family to go forward."